Effects of altitude acclimatization on blood composition of women

Abstract

The effects of altitude acclimatization on blood composition were studied in eight University of Missouri (elev 700 ft) coeds who lived on the summit of Pikes Peak (elev 14,000 ft) for 10 weeks. During the period of altitude exposure the following changes were observed: a transient increase in heart rate, the maximum being reached on 1st day of exposure; an early rapid increase in hematocrit and hemoglobin which later became more gradual; an early and sustained reduction in plasma volume; a rapid initial increase and a more gradual later increase in plasma protein concentration which was attributable to elevations in both the albumin and the globulin fractions; a sustained decrease in the albumin-to-globulin ratio; a slight but sustained increase in serum oncotic pressure; a slight but sustained decrease in blood water content and serum osmolarity; and finally, an unaltered total leukocyte count, but a significant increase in lymphocytes and significant decrease in monocytes. It is concluded that the hematopoietic response to altitude is markedly less in women than that usually observed in men. In women at least, dietary iron supplementation enhances the rate of hematocrit increase at altitude. And finally, the loss of plasma volume is felt to be real and not due to simple dehydration. high altitude; hypoxia; blood volume; blood hydration; plasma proteins; hematopoiesis; leukocytes; sex differences; iron supplement Submitted on April 3, 1968

Intermittent Hypoxic Training: Fact and Fancy

“…This period also allowed additional time to restore bone marrow iron stores in those athletes who were iron deficient. Previous work by the authors (Stray-Gundersen et al, 1993 and others (Hannon et al, 1969) demonstrated that individuals who are iron deficient are unable to increase the red cell mass in response to altitude exposure; (3) athletes were then randomized into one of three training groups (n 5 13 for each; 9 men, 4 women), where they were exposed for 4 weeks to (a) the primary experimental group, where the athletes lived at 2500 m and traveled down to a lower altitude of 1250 m once or twice per day to train (high-low); (b) an altitude control (high-high), where the athletes lived at 2500 m together with the hi-lo athletes, but did all their training at the same altitude or higher (2500-3000 m); and (c) a sealevel control, where the athletes traveled to a new training camp environment with mountainous terrain, but at sea-level altitude (low-low). The volume and relative intensity of training were closely matched among groups and followed the same pattern as the previous 4 weeks of training at sea level.…”

Erythropoietin down‐regulates proximal renal tubular reabsorption and causes a fall in glomerular filtration rate in humans

“…A similar mechanism to increase arterial oxygen content is seen when humans are exposed to high altitude. Here haemoglobin concentration and the arterial oxygen content are increased by a fall in plasma volume within the first day of exposure, and after approximately 12 days an increase in red blood cell mass also contributes to the normalisation of haemoglobin concentration (Hannon et al . 1969).…”

“…Here haemoglobin concentration and the arterial oxygen content are increased by a fall in plasma volume within the first day of exposure, and after approximately 12 days an increase in red blood cell mass also contributes to the normalisation of haemoglobin concentration (Hannon et al 1969). It appears beneficial that plasma volume is decreased in the acute presence of hypoxia since such a response increases oxygenation rapidly as compared with a mechanism depending exclusively on augmented erythropoiesis.…”

Hemoglobin Mass and Peak Oxygen Uptake in Untrained and Trained Female Altitude Residents

“…[15,17,31]). Astonishingly nearly all measurements of the latter quantities were done in males until now, in few cases data of both sexes were pooled.…”